This application relates to the art of switches and, more particularly, to manually resettable thermostatic switches that automatically move to an open condition responsive to an elevated temperature. The invention is particularly applicable to thermostatic switches that use a bimetal disc cooperating with a bumper for opening the switch contacts and will be described with specific reference thereto. However, it will be appreciated that the invention has broader aspects and can be used in other types of switches.
Devices such as appliances, heaters and furnaces commonly have a temperature limit switch for deactivating the device responsive to an undesirably elevated temperature condition. Reactivation of the device requires manual resetting of the switch. In some old designs, it was possible to override the temperature limit switch by holding a reset button down. This creates a dangerous condition because it allows the device to be operated even though an undesirably elevated temperature condition exists. In more recent designs, the switch remains open even though the manual reset button is held in its depressed reset position and this prevents overriding of the temperature limit switch. This application concerns the latter type of temperature limit switch.